Final answer:
To determine values not in the domain of a function, identify the range of input values for which the function is defined. Values outside this range, such as 90 in a data set ranging from 65 to 75, are not in the domain and yield unreliable results when used.
Step-by-step explanation:
To find values not in the domain of a function, one must understand what the domain represents. The domain of a function consists of all the input values (commonly x values) for which the function is defined. When working with real-world data, the domain is often constrained to the range of the observed data points.
As illustrated in Solution 12.10, if x values in a data set range between 65 and 75, any value outside of this range, such as 90, is not in the domain. Calculating a y value for an x outside the observed domain might yield a result, but it will not be considered reliable because it is based on extrapolation beyond the observed data.